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Spontaneous Occurrence of the Induced Cardioinhibitory Vasovagal Reflex
Author(s) -
ODDONE DANIELE,
BRIGNOLE MICHELE,
MENOZZI CARLO,
GIANFRANCHI LORELLA,
LOLLI GINO
Publication year - 1991
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/j.1540-8159.1991.tb04089.x
Subject(s) - medicine , vasovagal syncope , asystole , cardiology , anesthesia , syncope (phonology) , implantable loop recorder , reflex , vagovagal reflex , bradycardia , carotid sinus , heart rate , blood pressure , atrial fibrillation
ECG recording of spontaneous, neurally‐mediated syncope is rare. We have observed ten patients who sustained 70 syncopal episodes in whom: (1) EGG monitoring recorded syncope caused by ventricular asystole (AV block, three patients; sinus arrest; seven patients); (2) syncope and the spontaneously observed arrhythmias were reproducible by carotid sinus massage, upright tiit test, or eyebaU pressure; and (3) no discernable cause or precipiting factors were defected. Two patients had a history of cardiac disease and four patients had only mild nonclinical EGG or echocardiographic abnormalities. Syncopai episodes recorded during Holter monitoring were of sudden onset in four patients and preceded by prodromal symptoms in six patients. The maximum RR pause was 9.4 ± 3.7 seconds (range 4.5—15). Electrophysiological evaluation was normal in seven patients. Slight sinus node dysfunction or atrio‐ventricular conduction abnormalities were noted in three others. The clinical characteristics of spontaneous and induced episodes strongly suggest that increased vagal tone played a role in causing the spontaneous events. Vagal stimulation tests are useful for the diagnosis of syncope of unknown origin.